 Usage:  {mux,beta1,beta0,sigmax, sigmae,varbeta1,varbeta0} =eivknownvarumod(alpha,w,y,sigmau)  
 
 Input:

  alpha                  scalar 
                         
  w                      n x 1 matrix, the design variables 
                         
  y                      n x 1 matrix, the response 
                         
  sigmau                 scalar, the variance of measurement error sigma_u 
                         
 Output:

  mux                    scalar, the mean value of x 
                         
  beta1                  scalar, the estimate 
                         
  beta0                  scalar, the estimate 
                         
  sigmax                 scalar, the estimate of the variance of x 
                         
  sigmae                 scalar, the estimate of the variance of error e 
                         
  varbeta1               scalar, the estimate of the variance of the estimate of beta1 
                         
  varbeta0               scalar, the estimate of the variance of the estimate of beta0 
                         
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(C) MD*TECH Method and Data Technologies, 17.8.2000
